Support for scaffolds



June 13', 1939.

P. THOMSON SUPPORT FOR SCAFFOLDS 2 Sheets-Sheet 1 Filed Oct. 29, 1938INVENTOR. PETE? Thomson.

2 ATTORNzS.

BY a June 13, 1939- P. THOMSON 2,162,551

SUPPORT FOR SCAFFOLDS Filed Oct. 29, 1938 2 Sheets-Sheet 2 III/#147,174

INVENTOR.

PETE? Thomson.

E E m I Patented June 13, 1939 UNITED STATES PATENT OFFICE '7 Claims.

The present invention relates to trestles or scaffold supports and theprimary object of the invention resides in the provision of a supportfor scaffolding which is of extremely simple construction, yetexceedingly sturdy and capable of supporting heavy loads.

A further object of the invention is to provide a folding scaffoldsupport which may be quickly and easily set up and taken down, and whennot in use, may be folded into compact form for shipment or storage.

A further object resides in, the arrangement for retaining the supportin its folded condition by means which also serves to secure the supportto a scaffold beam.

A further object is to provide a scaffold support which may be set upfor use or taken down without requiring any tools, and which isadjustable to stand level and steady on uneven footing.

A still further object resides in the specific construction of theextensible supporting legs and the clamping means for securely retainingthe legs in adjusted position against relative movement between the legsections.

A still further object resides in the specific formation of the upperends of the angle iron leg members whereby the scaffold beam is firmlygripped between the legs without any twisting or canting of the legs dueto the clamping force.

Other objects and advantages of the invention will be apparent from thefollowing detailed description, taken in connection with theaccompanying drawings, forming a part of this specification and in whichdrawings:

Figure 1 is an elevation of the trestle or support set up for use with ascaffold beam supported thereby.

Figure 2 is a side view on a reduced scale of the showing in Figure 1.

Figure 3 is a rear view of the support or trestle in a folded position.

Figure 4 is an edge view of the trestle folded as in Figure 3.

Figure 5 is an enlarged section substantially on the lines 5-5 of Figure4.

Figure 6 is a fragmentary perspective view of the upper end portion ofone of the supporting legs.

Figure 7 is an enlarged section on the line 1-1 of Figure 3.

Figure 8 is a perspective view of a socket forming strap member of theclamping means for the extensible legs.

Figure 9 is a perspective view of a clamping shoe or block of theclamping means.

In the drawings and wherein like reference characters designatecorresponding parts thruout the several views, the letter A maydesignate generally the improved trestle or support and B a woodenscaffold beam or plank supported by the trestle.

The trestle A comprises a metal frame embodying a pair of upwardlyconverging extensible supports I0 each of which includes an upper mainsection or leg I l and a lower extension section or leg I2 nestled inthe section I I in a manner to permit relative longitudinal movement forvarying the height of the trestle. These leg sections I I and I2 areformed from angle iron, with the extension section I2 being slightlysmaller in size and slidably fitting in the main section II as shown inFigures 5 and '7. As will also be seen from Figures 5 and 7, the legsections I I are what are known as square root angles, that is, theflanges form a sharp internal corner, while the leg sections I2 may beordinary angle iron having a slightly rounded internal corner and asharp external corner.

The legs II are arranged with the flanges I3 in confronting relation,and the flanges I4 thereof directed toward one another whereby the upperextremities of the flanges l4, provide sharp corners or biting edges I5which are adapted to grip and bite into opposite faces of the woodenbeam B. An upper end portion of the flange I3 is bent inwardly over theupper end edge of the flange I4 as at IE to form a stop flange having astraight bearing edge I'I perpendicular to the flange I 4. This bearingedge I1 is spaced slightly from the biting edge I5 and is adapted toengage thruout its length, a face of the beam B and prevent twistingstrains on the legs when clamped upon the beam.

The leg sections II are connected adjacent their lower ends by a solidor one-piece spacer or cross bar I8 having its ends pivotally secured tothe legs by rivets I9 whereby the upper portions of the legs are freelymovable toward and from one another. As shown in Figure 5, the rivets I9have beveled heads countersunk in the flange I4 to lie flush with theinner surface of the flange. The bearing for the rivet I9 is formed bypunching the metal of the flange to form a short sleeve like projectionwhich slightly spaces the cross bar I8 from the flange.

Adjustably connecting the upper portions of the legs II is a combinedsupport and clamping means embodying a carriage bolt 20 having a squaredshank portion adjacent the head 2I fitting in a square opening in theflange I 3 of one of the legs I I and its threaded end 22 extending thruan opening in the flange l3 of the other leg II. The bolt 20 is bentsubstantially midway of its ends forming a V-seat for the beam B to restin. Threaded upon the end 22 of the bolt outwardly of the flange I3 is ahand nut 23 having a hand lever 24. Turning of the nut 22 by its lever24 will draw the upper ends of the supports I0 toward each other so asto firmly grip the beam B between the upper ends of the legs II with thebiting edges I5 biting into the beam and the bearing edges I1 bearingagainst opposite faces of the beam. Provided on the shank of the bolt20, inwardly of the flanges l3, are two pins or the like 25 formingstops against which the flanges I3 abut and limit movement of the legs II toward one another when the trestle is folded as in Figure 3. Thesestops 25 are so spaced that when the hand nut 23 is turned tight infolding the trestle, the biting edges I5 will be slightly spaced apartto prevent being damaged.

Pivotally connected at one end as by a rivet 26 to each of the legs IIat a point adjacent the lower end of the leg, are straight diagonalbrace rods 21 having free ends adapted for clamping engagement with thebeam B at a point spaced from the supports I6. As shown in Figure 5, therivets 26 have beveled or countersink heads which are countersunk in theflange I3 to lie flush with the inner surface of the flange. The bearingfor the rivet 26 is formed by punching the metal of the flange I3 toform a short sleevelike projection which slightly spaces the brace rodfrom the flange and forms somewhat of a loose pivotal connection. Thisloose pivotal connection of the brace rods 21, together with the slightspacing of the pivoted ends from the flanges I3, permits the braces tochange their angular relation when moved without creating anobjectionable binding action at their pivot points.

Extended thru suitable openings adjacent to the free ends of the bracerods 21 is a clamping bolt 28 provided with a hand nut 29 having a handlever 36. The hand nut 29 when tightened by the lever 38 serves to drawthe free end of the brace rods together and into clamping engagementwith the beam B when the trestle is set up for use. The clamping bolt 28as shown in Figures 3 and 4, is so spaced from the pivot 26 of the bracerods 21 as to be disposed slightly beyond the beam engaging ends of thesupports II] when the trestle is folded, thereby allowing the brace rodsto overlie their respective supports as shown in Figure 4.

The free ends of the'brace rods 21 are provided with inwardly directedpointed calks or spurs 3| having shanks extended thru openings in thebrace rods and upset to form driving heads 32 which may be tapped with.a hammer or the like for firmly forcing the spurs into the wooden beamin addition to the clamping action of the bolt 28 and securely attachthe braces to the beamagainst movement.

Each of the supports I6 is separately adjustable for varying 'the"height of the trestle and for leveling the trestle on uneven footings.The clamping means for the extensible supports i6 comprises a metalstrap member 34 connected diagonally-across-the lower portion of theupper legs section II as by welding the ends of the strap'member totheedges of the flanges I 3 and I4 as shown'inFigure 7. Theintermediateportion of the strap member 34 is drawn in at the side edgesof the member to form a socket 35 having parallel side walls 36 and atop wall 31. Provided in this top wall 31 is an opening 38.

Adapted for co-action with the strap member 34 is a right triangularclamping shoe or block 40 having grooved right angularly gripping faces4| and a diagonal face 42. The clamping shoe 4!] is adapted to bedisposed inwardly of the strap member 34 and is provided at each end ofthe face 42 with side or retaining extensions 43 which slidably engagethe outer surfaces of the side walls 36 of the strap member forconstraining the clamping shoe to movement toward and from the strapmember. Provided in the diagonal face '42 of the clamping shoe is asocket 44 adapted to receive the inner threaded end portion 45 of anL-shaped clamp screw 46. The threaded portion 45 of the clamp screwextends thru the opening 38 in the strap member 34 and is threaded thrua pressure nut 41 disposed in the socket 35 and held against rotationbetween the parallel side walls 36 of the socket. As shown in Figure '7,when the clamp screw is threaded inwardly, the grooved gripping faces 4|of the clamping shoewill be forced into engagement with the flanges ofthe leg I2 and clam-p these flanges firmly against the flanges I3 and I4of the upper leg section II. The specific formation of the leg sectionsII of square root angles insures a positive and firmer gripping of theleg section l2 with the leg section II when the clamp is tightened.

The lower leg section I2 which is slidable inwardly of the upper legsection II has one of its flanges bent over the end edge of itscompanion flange to form a rest flange or foot 48.

In assembling the supports II), the clamp screw 46 is first backed offand the clamping shoe placed in position beneath the strap member 34.The leg section I2 is then slid between the shoe and the flanges of theleg section II After the leg sections H and I2 are so assembled and withthe clampingshoein place, a retaining pin 50 which may be in the form ofa screw nail is then driven into a suitable opening adjacent the upperend of the leg I2 and forms a stop engageable with 'an end of the shoe4!] and prevents full withdrawal of the leg I2 from beneath the clampingshoe when extending the supports Hi. When the leg sections II and I2 areassembled as in Figure '7, the clamping shoe 40 will be retained inplace even though the clamp screw 46 is completely removed.

In setting up or erecting the trestle, the scaffold beamis placedbetween the upper ends of the supports Hland restin the bend of the combined supporting and clamping bolt 20. Thehand nut 23 is then tightenedfor clamping the beam between the upper ends of the supports with thebiting edges I5 biting into the beam and the bearing edges I'I engagingoppositeside faces of the beam, as'in Figure l. The bearing edges I'Ithru contact longitudinally of thebeam, will prevent canting or twistingof the leg sections II when considerable clamping pressure is applied bythe clamping means. The brace rods 21 are then swung on their pivots I9to straddle the beam at their free ends and after which the clampingbolt28 is tightened for clamping the free ends of the brace rods upon thebeam. To assist in firmly engaging the free ends of the brace rods withthe beam, the heads 32 of the calks -3I maybe tapped with a hammer fordriving the'pointed calksinto the-beam. 'If the-support IO haspreviously been adjusted-to-height, the final adjustment of the legs maybe made for leveling the trestle and providing a firm footing for thelegs. When collapsing or folding the trestle for storage or shipment,the lower leg sections l2 are first slid into the leg sections I l andretained by means of the clamping shoe 40. The hand nut 23 is thenturned up until the flanges I3 of the leg II are drawn up tight againstthe stops 25, and which occurs prior to engagement of the biting edgesl5. The convergent brace rods 21 are then swung so as to overlie theflanges l3 as in Figure 4 and. then the clamping bolt 28 tightened toclamp the brace rods upon the supports Ill. Thus, the clamping bolt 20serves the dual purpose of supporting the scaffold beam and alsoclamping the supports upon the beam, while the clamping bolt 28 servesthe dual purpose of clamping the brace rods to the scaffold beam andalso clamping the brace rods upon the supports I when the trestle isfolded.

Changes in detail may be made to the form of invention herein shown anddescribed, without departing from the spirit of the invention or thescope of the following claims.

I claim:

1. In a scaffold beam support, a support comprising upper and lowerangle iron leg sections,

a sheet metal strap member connected across the flanges of the upper legsection and having its intermediate portion formed into a socket, a nutheld against rotation in said socket, a right triangular clamping shoeretained in position by the strap member for engagement with the lowerleg sectionand having a socket in its diagonal face,

and a clamping screw threaded thru the nut and having its free endengaging in the socket of the clamping shoe for clamping the legsections in longitudinally adjusted relation.

2. In a support for scafiold beams, an extensible leg including upperand lower leg sections of angle-shape formation and with the lower legsection nested in the upper leg section, and clamping means forretaining the leg sections in longitudinally adjusted relationcomprising a strap member secured to and extending across the inner sideof the upper leg section, a socket formed in the strap member, a nutretained against rotation in the socket, a right triangular clampingshoe for engaging in the angle of the lower leg section, and a clampingscrew having a threaded portion threaded thru said nut and acting uponthe clamping shoe for forcing the shoe into binding contact with theinner leg section.

3. In a clamp for extensible supports of angle iron shape and having oneangle iron nested within the other, a strap member secured across theflanges of the outer angle member, a socket formed in the strap member,a nut loosely retained against rotation in the socket, a righttriangular clamping shoe held against displacement by the strapmemberand adapted for clamping engagement with the inner angle member, and aclamping screw threaded thru the nut and acting upon the clamping shoefor clamping the shoe against the inner angle member.

4. In a scaffold beam support, a frame including. extensible supportseach comprising an upper angle-shaped leg section and a lowerangleshaped leg section nested in the upper leg section, clamping meanscarried by the lower portion of the upper leg section including aclamping shoe, a clamping screw for moving the shoe into clampingengagement with the lower leg section, and a pin projecting from oneflange of the lower leg section and engageable with said clamping shoefor limiting outward movement of the lower leg section, said lower legsection when nested in the upper leg section preventing displacement ofthe clamping shoe should the clamping screw be removed.-

5. In a scaffold beam support, a pair of upwardly converging legs, apivotally connected spacer bar for the lower portions of the legs, aclamping bolt adjacent the upper ends of the .legs having angularlydisposed portions one of which is provided with a head and the otherportion with a threaded section, a hand nut threaded upon the threadedsection for drawing the legs together, and a pin in each angular portionof the bolt and limiting movement of the legs together at their upperends 6. In a scaifold beam support, a frame including a pair ofsupports, clamping means for drawing the supports together at theirupper ends into clamping engagement with the scaffold beam, a brace rodpivoted at one end to each support, a clamping bolt for the free ends ofthe brace rods for clamping the free ends upon a scaifold beam, and apointed calk at the free end of each brace rod and having shanks passedthrouthe rods and headed up at the outer sides of the rods to formdriving heads for forcing the calks into the beam.

'7. ,In a s'caifold beam support, a frame including a pair of upwardlyconverging angle iron legs each having the upper end of the free edge ofone flange providing a biting corner for biting into a scaffold beam,and the upper portion of the companion flange of the leg being bent tooverlie the upper edge of said first mentioned flange and terminatingshort of the free edge of said first flange to form a straight bearingedge extending normal to the major plane of the frame at one side of thebiting cornerfor bearing contactwith the scaifold beam longitudinally ofthe beam.

PETER THOMSON.

